[Neurosarcoidosis. Review of the literature]

Sarcoidosis is a systemic granulomatous disease of unknown etiology. The frequency of neurologic manifestations varies from 5 to 15% of cases. Systemic manifestations of sarcoidosis are often present and the diagnosis is still based on histopathological studies. In nearly half of the patients no systemic manifestations are found and the diagnosis of sarcoidosis may be difficult. Main neurologic involvements are cranial and peripheral nerve lesions. Other manifestations include aseptic meningitis, hydrocephalus, parenchymatous granulomata of the central nervous system, hypothalamic dysfunction and myopathies. There is more than one manifestation of neurosarcoidosis in 30% of the patients. Lumbar puncture is useful to rule out other diseases but CSF changes are not specific, neither elevated serum angiotensin converting enzyme levels. Computed tomography is helpful, but magnetic resonance imaging is the best diagnostic tool. The granulomatous nature of the disease can only be confirmed by tissue sampling and brain biopsies are sometimes required. There have been no controlled trials of treatment for neurosarcoidosis but corticosteroids are the main stay of therapy. The prognosis is often good and 55% of patients reported have had a complete recovery. In case of failure, immunosuppressive and radiation therapy can be used. Surgery is indicated to establish tissue diagnosis, in the presence of increased intracranial pressure, or to remove brain tumor.